1. Field of the Invention
The present invention relates to a regulator for chip biasing and related control methods, and more particularly, to a regulator capable of charging a regulator capacitor with a pre-charging circuit so as to prevent a current-capture transistor of the regulator from generating initial currents that are too high, and related control methods.
2. Description of the Prior Art
In modern information society, a variety of electronic information apparatuses, such as cell-phones, personal computers and network servers, are all fabricated based on a microprocessor control system. How to enable a microprocessor to function normally is therefore becoming one of the most important R&D topics of modern information industry.
In general, a microprocessor control system is realized by one or more than one chips installed on a circuit board, like a printed circuit board. In order to achieve high integration, low power consumption and fast operation speed, a core circuit, which is installed in the chip for data calculation and information manipulation, is always biased by a low voltage and generates electrical signals of low levels correspondingly. However, low-leveled signals do not have the capability to drive data in the core circuit to circuits outside of the chip and vice versa, so the chip usually further comprises an I/O circuit as an I/O buffer. Since both data and signals that the core circuit manipulates are of low levels, these data and signals cannot be transmitted to a region outside of the chip unless they have been pumped by the I/O circuit to become data and signals of high levels. On the contrary, data transmitted from the region outside of the chip to the chip are to be transformed by the I/O circuit to become data of low levels.
A regulator, capable of generating a regulated voltage of a low level by referring a direct voltage of a high level, is usually for biasing the core circuit with the regulated voltage to bias the I/O circuit with the direct voltage. According to the prior art, the regulator is realized by a Zener diode. One end of the Zener diode is reversed biased by the direct voltage and the other end of the Zener diode outputs the regulated voltage, which is equal to a voltage difference between the direct voltage and a voltage across the two ends of the Zener diode.
However, the regulated voltage that the prior art regulator generates is neither precise nor stable.